Process of producing a sound track on a light-sensitive color film



Patented Nov. 194i) UNITED STATES.

PATENT OFFICE PROCESS OF PRODUCING A SOUND TRACK ON A LIGHT-SENSITIVE COLOR FILM Wilhelm Schneider, Dessau,

Anhaltiand Gerd Heymer, Wolfen, Kreis Bitterield, Germany, assignors, by mesne assignments, to General Aniline & Film Corporation, New York, N. Y., a corporation of Delaware No Drawing. Application January 5, 1937, Serial No. 119,078. In Germany January '9, 1936 1 Claim. (01.95-2) the picture. For example, in order to obtain a definite gradation of the sound track for any particular sound system it would produce unfavorable picture gradation if thev picture and the sound track were developedsimultaneously. The present'invention is based on the observation that in the development of color pictures a sound track which is produced by color development, is strongly transparent to infrared rays. Such films is illfitted for the modern sound film machine which is operated with caesium cells sensitive to the infra red ray.

' This invention relates to a process for treating the sound track of a silver halide emulsion layer containing color components in one or more of the development operations necessary for producing the color picture, separately from the 30 ,picture and so that the soundtrack is non-transparent to infra-red. By color components there are to be understood components of quinoneimine and azomethine dyes'tufis as they are described in U. S. Patent 1,102,028. These are par- 35 ticularly suited forthe present purpose, if they are fast to diffusion, that is to say if they contain special groups which prevent these componentsirom wandering'in' the emulsion. Such groups are specified for instance in French Patent 40 803,566, French Patent 807,792, Italian Patent a 343,581, U. S. A. applications Ser. No. 111,250

filed Novemberl'l, 1936, Ser. No.,;"12,718 filed, April 4, 1936, Ser. NO. 90,726 filed J y 1.5, 1936' and Ser. No. 94,340 filed August 5,. 936. Other 'M color components' which may also come into question are components or azo-dyestufls and from these particularly those which are fast to diflfus'ion.

.In'the' production of a color sound film by the 4 reversal process, for example, the sound track,

after the first development which in known manner produces a pure silver negative, is covered by a varnish insoluble in the subsequently applied baths and this varnish is only removed after completely finishing the color .reversal picture and 5 the track is then fixed and there is obtained a silverblack sound track on t negative.

In a negative positive process, the negative film needs no treatment separate from the sound track, there being obtained a sound track formed of dyestuif. In copying this film, one must according to the invention, after the development and before the silver picture is removed by dissolution, varnish the sound track, then finish the picture byflbleaching or dissolution of the silver, dissolve away the varnish and fix the film. There is then obtained in addition to a sound track in silver a superimposed sound track in dyestuff. Obviously the picture and the sound track can be treated together, in which case after the .dissolution of the silver picture there is obtained a sound track in pure dyestufi'.

Instead of varnishing the track the separate treatment for the picture and the sound track may consist in developing the film in horizontal upright position and only immersed so far in the liquid as is necessary for the separate development of picture and track. This method is of particular advantage and may be simplified if the sound track lies outside the perforations. I

Instead of producing acolor sound track superimposed upona silver sound track the infra-red absorption of the dyestuff produced by the de-" velopment 'can also be strengthened by treatment oi the color sound track with a metal salt, for instance, a salt of'chromium, iron or copper, in which case the silver may remain in the color sound track or be dissolved therefrom in known manner. In'this case there is usedwlth advantage a dyestufl. containing an atom grouping 40 which is suitable for complex combination with a metal salt. Such dyestuffs are sumciently well known in color chemistry [see for instance Fierz- David: Kilnstliche 'organische Farbstofle (1926)", page generally they contain an]! OH-group having a tendency for the complex formation, produced by another group, for example a .carboxylic I r a hydroxyl group. The

- following are examples f color components which combine with the oxidized products of a suitable developing substance, as for instance of a developing substance containing a free aminogroup, such as diethylamino-aniline-hydrochloride, to form such dyestuffs.

A suitable component for a yellow dyestufi is for instance p-capronyl-amino-benzoyl-acetylamino-salicylic acid of the following formula:

omit-o NHO-CQCHLCQNHQOH COOH A component for a blue dyestufi is the l-hydroxy- 2-carboxy-B-dodecylamirio-naphthalene of the following formula:

NH. CnHu A component for a red dyestufi is 1(4.hyroxy- 3-carboxy-phen'yl) 3-4 zdodecoyl-aminophenyl-5- pyrazolone of the following formula:

COOH

0H Another possibility to make the sound track of a color film non-transparent to infra-red r-ays isto color the silver of the sound track by a toning process. The following examples serve to illustrate this part of the invention:

1. A film with three silver halide emulsion layers containing color components fast to diffusion arranged in superimposed relationship on one or both sides of a support is after exposure to light subjected to a color forming-development during which besides the dyestuif images formed by the combinatibn of the components a superimposed silver image is formed in the three single layers. This silver image has to be moved in order .to obtain the pure dyestufl images in the picture area of the film. Before the baths nec-' essary for this purpose are applied the sound track which has also been developed during the .position through the treating liquors.

liquids which are applied for oxidizing the silver so that the film may be'finished without any intermediate drying process.

2. If the color pictures of the photographic material described in Example 1 are to be produced according to a reversal process the following two proceses may be applied:

a. After the first development which is carried a film of the type described above in the area of the sound track is transformed into a blue silver ferro-cyanide picture by leading it in upright *Ther'eout by means of a non-color forming developer,

after the second development is carried through Good results are also obtained if the 'silver of the sound track is toned by means of sulfur toning baths. According to these two examples the silver of the sound track before the transformation of the silver of the picture area into a compound soluble-in the ordinary treating baths is protected from the removal by transforming it into compounds which may easily be scanned during the production of the film. If the dyestuffs produced during the developing process lie in the area of the sound track and are detrimental to the scanning of the sound track they may be destroyed at the same time as the transformation image of the sound track silveror in a separate bath.

What we claim is:

The method of producing three-color cinematographic sound, films in a three-layer material for color forming development, said multi-layer material comprising a support and l a silver halide emulsion containing p-capronyl-aminobenzoyl-acetyl-amino-salicyclic acid, a second layer containing 1-hydroxy-2-carboxy-5-dodecylamino-naphthalene, and a third layer containing 1-(4'-hydroxy-3-carboxy-phenyl) -3 4'-dodecylaminophenyl-5-pyrazolone, which method comprises separately exposing the picture and sound area of said film, developing all three layers of the picture area and the sound area by color forming development in a single developing op eration, treating the sound area with a salt of a metal selected from the group consisting of chromium, iron and copper and removing the silver developed in all the layers. u

- v 'WJLHELM SCHNEIDER.

GERD HEYMER. 

